Critical Intraoperative Detection of Microbubbles in Veno-Veno-Arterial ECMO Support With Impella: A Case Report of Peripartum COVID-19 Myocarditis.

Microbubbles during extracorporeal membrane oxygenation (ECMO) can cause systemic embolism. We report a 33-year-old woman in late pregnancy with COVID-19-associated myocarditis supported by veno-veno-arterial ECMO and Impella 5.5. During rapid transfusion via central venous catheter for massive hemorrhage after emergency cesarean section, transesophageal echocardiography (TEE) revealed microbubbles entering the arterial circulation. The bubbles resolved after pausing transfusion. Although the patient initially recovered without neurological deficits, she later died from unrelated intracranial hemorrhage. This case highlights the need to prevent air entrainment during transfusion and illustrates the diagnostic value of intraoperative TEE in detecting systemic microembolism under mechanical circulatory support.